Two-dimensional checkerboard lattice, the simplest line-graph lattice, has been intensively studied as a toy model, while material design and synthesis remain elusive. Here, we report theoretical prediction and experimental realization of the checkerboard lattice in monolayer Cu2N. Experimentally, monolayer Cu2N can be realized in the well-known N/Cu(100) and N/Cu(111) systems that were previously mistakenly believed to be insulators. Combined angle-resolved photoemission spectroscopy measurements, first-principles calculations, and tight-binding analysis show that both systems host checkerboard-derived hole pockets near the Fermi level. In addition, monolayer Cu2N has outstanding stability in air and organic solvents, which is crucial for further device applications.
@article{arxiv.2306.05634,
title = {Realization of a two-dimensional checkerboard lattice in monolayer Cu$_2$N},
author = {Xuegao Hu and Run-Wu Zhang and Da-Shuai Ma and Zhihao Cai and Daiyu Geng and Zhenyu Sun and Qiaoxiao Zhao and Jisong Gao and Peng Cheng and Lan Chen and Kehui Wu and Yugui Yao and Baojie Feng},
journal= {arXiv preprint arXiv:2306.05634},
year = {2023}
}